The length of telomeres and its control mechanism by telomerases decide the lifetime of cells. Understanding how this mechanism works will provide deeper insight on how to control the proliferation of tumor cells and may have direct impact on anticancer drug designs. Formation of G-quartets by G-rich sequences inhibits extension of the DNA sequence by telomerase in vitro. The inhibitor that is able to bind quadruplexes may therefore serve as a potential agent to inhibit the proliferation of tumor cells. In order to understand the details in the interactions between the inhibitor and the quadruplex, their complex structure is being studied through NMR spectroscopies. Solving the NMR structure depends on access to Computer Graphics Laboratory resources: assignments are aided by the software packages, NMRPipe and Sparky, structural calculations depend on DYANA and MARDIGRAS, visualization of structures will be done using MidasPlus and structure refinement will include back calculations through CORMA.